Nickel-zinc alloy catalyst doped with metal oxide aid as well as preparation method and application of nickel-zinc alloy catalyst

Abstract

The invention aims to provide a nickel-zinc alloy catalyst doped with a metal oxide auxiliary agent and a preparation method and application thereof, and belongs to the technical field of waste gas treatment and environment-friendly catalytic environment, the molecular formula of the catalyst is NixZn (at) yMOn-Al2O3, x represents the feeding molar ratio of nickel to zinc, y represents the mass fraction of the auxiliary agent, and y represents the mass fraction of the auxiliary agent. MOn represents oxides of different alkaline earth metals or rare earth metals; the catalyst has good catalytic performance in a methane dry reforming reaction, the CH4 conversion rate can be about 46%, the CO2 conversion rate can be about 70%, the hydrogen-carbon ratio of the product synthesis gas is about 1, and no carbon deposition is generated in a 100-hour stability test.

Description

Technical Field

[0001] The invention belongs to the technical field of waste gas treatment and environmental catalytic environment, and specifically relates to a nickel-zinc alloy catalyst doped with a metal oxide additive, a preparation method and an application thereof. Background Art

[0002] As the concept of circular economy has gained popularity, the conversion and utilization of biomass has received widespread attention. Some biomass gas can be used to replace fossil fuels to prepare synthesis gas. Biogas is an important renewable biomass energy source, with its main component being about 60% methane (CH 4 ), 30% carbon dioxide (CO 2 ), 0-5% nitrogen (N 2 ) and less than 1% hydrogen (H 2 ) etc. If biogas is directly discharged, a large amount of CH 4 and CO 2 As a major greenhouse gas, it will have a huge impact on the environment, climate change, and the balance of the ecosystem. 4 and CO 2 As important carbon-containing resources, the methane dry reforming (DRM) route can realize the resource utilization of these two gases, and the prepared synthesis gas can be further converted into downstream high-value-added products through Fischer-Tropsch synthesis. Therefore, with the help of the methane dry reforming reaction route, methane and carbon dioxide-rich gases such as biogas, coke oven gas, and relaxation gas can be fully recycled and utilized, which has good economic benefits and effectively extends the processing chain of biomass chemical and coal chemical products.

[0003] Methane dry reforming reaction is a strong endothermic reaction with volume increase, and the critical temperature is 640℃. It requires a higher temperature to react, so it is often necessary to add a catalyst to reduce the reaction energy barrier. However, when the temperature is between 557℃-700℃, it is accompanied by side reactions of methane cracking and CO disproportionation, and the byproduct C α Can be CO 2 , H 2 O, H 2 Restore, but at the same time C α It can also form C β Species, C. β The activity is low and it is not easy to convert. It is easy to form encapsulated graphite carbon or filamentous carbon, which blocks the active metal sites of the catalyst. Especially in gases such as biogas, when there is an excess of methane, the carbon deposition caused by methane cracking at high temperature is more serious, and the catalyst deactivation rate is faster. At the same time, due to the existence of the reverse water gas side reaction, H 2 Consumption and CO 2 The formation of the product synthesis gas (H 2 / CO) ratio is lower than 1, which is not conducive to direct use as chemical feed gas. Properly increasing the methane ratio can regulate the hydrogen-carbon ratio. Therefore, it is crucial to improve the catalyst's anti-carbon deposition performance in methane-rich dry reforming reactions.

[0004] Among the catalysts used for DRM reactions, precious metals such as Ru, Rh, Pd, and Pt are used as active metal components with good performance but high cost. Non-precious metals commonly use Ni-based catalysts, which have activity rates comparable to those of precious metals, but are prone to carbon deposition and high-temperature sintering, which can lead to catalyst deactivation. One of the effective strategies is to improve the activity and stability of the catalyst by introducing transition metals to form alloys with Ni. Among them, nickel-zinc alloys promote the circulation of C by expanding the gap radius of the cubic Ni octahedron; secondly, different carriers and additives can also affect the catalytic activity. Enhancing the alkalinity of the carrier is conducive to the adsorption of CO. 2 , thereby accelerating C α By introducing a small amount of alkaline earth metal oxides or rare earth metal oxides as additives, the acidity and alkalinity of the catalyst, the interaction between the active components and the carrier, and the electron density of the metal atoms are regulated, thereby improving the performance of the catalyst and its ability to resist carbon deposition. Summary of the invention

[0005] The purpose of the present invention is to provide a nickel-zinc alloy catalyst doped with a metal oxide additive and a preparation method and application thereof. The catalyst prepared by the method can achieve CO 2 With CH 4 Stable conversion, good anti-carbon deposition performance of the catalyst, and the ratio of the prepared synthesis gas (H 2 / CO 2 ) reaches 1, which is conducive to meeting the downstream industrial processes.

[0006] The present invention adopts the following technical solution: A nickel-zinc alloy catalyst doped with a metal oxide additive, comprising metal Ni, metal Zn, and metal oxide Al 2 O 3 , doped additives alkaline earth metal oxides or rare earth metal oxides MO n Composition; the molecular formula of the catalyst is Ni x Zn@yMO n -Al 2 O 3 , where: x represents the molar ratio of nickel and zinc, y represents the mass fraction of the doped additive, MO n Represents oxides of different alkaline earth metals or rare earth metals.

[0007] Furthermore, 1≤x≤3.

[0008] Furthermore, the auxiliary agent MO nThe mass fraction y is 1 wt%-5 wt%.

[0009] Furthermore, the content of the metal Ni is 34 wt%-62 wt%.

[0010] Furthermore, the alkaline earth metal oxide or rare earth metal oxide MO n Including MgO, CaO, CeO 2 ,La 2 O 3 At least one of .

[0011] A method for preparing a nickel-zinc alloy catalyst doped with a metal oxide additive comprises the following steps: The first step is to prepare an alkaline solution: fully dissolve the soluble carbonate to obtain solution A, and evenly disperse the zinc source ZIF-8 in solution A; The second step is to prepare a metal ion solution: fully dissolve the nickel salt solution, the aluminum salt solution, and the soluble salt containing the metal element M to obtain a solution B; The third step is to synthesize a metal oxide precursor: add solution B to solution A, add a precipitant to adjust the pH to 8-12, stir evenly and let stand, centrifuge and wash until the solution is neutral, dry and then calcine to obtain a metal oxide precursor; Step 4: Reduction: The metal oxide precursor is heated in H 2 The catalyst is reduced under a nitrogen atmosphere to obtain the nickel-zinc alloy catalyst doped with the auxiliary agent.

[0012] Furthermore, the soluble carbonate in the first step includes sodium carbonate or potassium carbonate, and the concentration of solution A is 1-2 mol / L.

[0013] Furthermore, in the second step, the nickel salt includes one or a mixture of nickel nitrate, nickel sulfate, and nickel acetate, and the concentration of the nickel salt solution is 0.5-2 mol / L; the aluminum salt includes one or a mixture of aluminum nitrate, aluminum sulfate, aluminum acetate, and pseudo-boehmite, and the concentration of the aluminum salt solution is 0.5-2 mol / L.

[0014] Furthermore, in the second step, the molar ratio of the nickel salt solution to the aluminum salt solution is 3-1:1.

[0015] Furthermore, the soluble salt containing the metal element M in the second step includes any one or a mixture of nitrate, sulfate and acetate, and the concentration of the soluble salt solution containing the metal element M is 0.5-2 mol / L.

[0016] Furthermore, the precipitant in the third step includes any one of urea, ammonia water, sodium hydroxide, potassium hydroxide, and a mixed precipitant of EDTA and sodium hydroxide.

[0017] Furthermore, in the third step, the calcination temperature is 400-600° C., and the calcination time is 2-5 hours.

[0018] Furthermore, in the fourth step, the reduction temperature is 400-600° C., the reduction time is 2-5 hours, and the concentration of hydrogen in the reduction environment is 10-100%.

[0019] A nickel-zinc alloy catalyst doped with a metal oxide promoter is used in methane-rich dry reforming reaction.

[0020] The preparation method of the nickel-zinc alloy catalyst doped with a metal oxide additive effectively improves the stability and anti-carbon deposition performance of the catalyst, so that it can still achieve stable conversion of methane and carbon dioxide under harsh conditions of methane-rich, and the synthesis gas (H 2 / CO) reaches 1. In addition, the catalyst adopts the coprecipitation synthesis method, which avoids the disadvantages of high temperature and high pressure and long cycle of hydrothermal synthesis, is simple to operate and low cost. After doping with additives, the interaction between metal and carrier is effectively improved, the metal particles are evenly dispersed, and the acid sites on the surface of alumina carrier are modified, the basicity of the catalyst surface is increased, and its effect on CO 2 The molecules have stronger adsorption and activation capabilities and can promptly convert the C atoms produced by methane cracking to avoid the formation of CC bonds that may cause catalyst deactivation.

[0021] The beneficial effects of the present invention are as follows: The above technical solution of the present invention can synthesize a nickel-zinc alloy catalyst doped with a metal oxide additive. On the one hand, the catalyst solves the problem that methane cracking easily occurs under methane-rich conditions, resulting in carbon deposition and deactivation of the catalyst, and effectively improves the stability of the catalyst. On the other hand, the catalyst exhibits good CH 4 and CO 2 activity, which can regulate the product synthesis gas (H 2 / CO) ratio reaches 1, which meets the needs of high value-added chemical product manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the XRD pattern of the precursor before calcination in Example 1.

[0023] Figure 2 This is the SEM image of the precursor before calcination in Example 1.

[0024] Figure 3 This is the XRD pattern of the metal oxide precursor in Example 1.

[0025] Figure 4 This is the SEM image of the metal oxide precursor in Example 1.

[0026] Figure 5 This is the BET diagram of the metal oxide precursor in Example 1.

[0027] Figure 6 This is the XRD pattern of the metal alloy catalyst in Example 1.

[0028] Figure 7 This is the SEM image of the metal alloy catalyst in Example 1.

[0029] Figure 8 This is the catalyst stability test diagram of experimental group 2.

[0030] Fig. 9 This is the XRD pattern of the catalyst after the stability test of experimental group 2. DETAILED DESCRIPTION

[0031] Example 1 A method for preparing a nickel-zinc alloy catalyst doped with a metal oxide additive comprises: Step S1: Dissolve 7.95 g of anhydrous sodium carbonate in 100 mL of deionized water, stir evenly, then add 2.15 g of ZIF-8 to the solution, stir for 30 min, and obtain a milky white solution.

[0032] Step S2: Take 8.72 g Ni(NO 3 ) 2 6H 2 O, 3.75 g Al(NO 3 ) 3 9H 2 O, 0.47g Ca(NO 3 ) 2 ·4H 2 O, dissolved in deionized water, stirred for 30 min to fully dissolve the salt solution, added the salt solution dropwise to the milky white solution, added the precipitant NaOH, adjusted the pH to 10, stirred evenly, transferred the above solution to a centrifuge cup, and centrifuged at 4500 r / min for 3 min to obtain the product. The product was centrifuged again with distilled water, washed to neutrality, and then dried in an oven to obtain a green solid powder. Finally, it was placed in a muffle furnace and calcined at 500°C for 3 h at a heating rate of 2°C / min to obtain the metal oxide precursor NiO-ZnO@2.5CaO-Al 2 O 3 .

[0033] Step S3: The metal oxide precursor NiO-ZnO@2.5CaO-Al 2 O 3 The metal alloy catalyst Ni was obtained by reduction at 550℃ in hydrogen atmosphere for 2 h. 3Zn@2.5CaO-Al 2 O 3 .

[0034] Example 2 A method for preparing a nickel-zinc alloy catalyst doped with a metal oxide additive comprises: Step S1: Dissolve 7.95 g of anhydrous sodium carbonate in 100 mL of deionized water, stir evenly, then add 2.15 g of ZIF-8 to the solution, stir for 30 min, and obtain a milky white solution.

[0035] Step S2: Take 8.72 g Ni(NO 3 ) 2 6H 2 O, 3.75 g Al(NO 3 ) 3 9H 2 O, 0.94 g Ca(NO 3 ) 2 ·4H 2 O, dissolved in deionized water, stirred for 30 min to fully dissolve the salt solution, added the salt solution dropwise to the milky white solution, added the precipitant NaOH, adjusted the pH to 10, stirred evenly, transferred the above solution to a centrifuge cup, and centrifuged at 4500 r / min for 3 min to obtain the product. The product was centrifuged again with distilled water, washed to neutrality, and then dried in an oven to obtain a green solid powder. Finally, it was placed in a muffle furnace and calcined at 500°C for 3 h at a heating rate of 2°C / min to obtain the metal oxide precursor NiO-ZnO@5.0CaO-Al 2 O 3 .

[0036] Step S3: The metal oxide precursor NiO-ZnO@5.0CaO-Al 2 O 3 The metal alloy catalyst Ni was obtained by reduction at 550℃ in hydrogen atmosphere for 2 h. 3 Zn@5.0CaO-Al 2 O 3 .

[0037] Example 3 A method for preparing a nickel-zinc alloy catalyst doped with a metal oxide additive comprises: Step S1: Dissolve 7.95 g of anhydrous sodium carbonate in 100 mL of deionized water, stir evenly, then add 2.15 g of ZIF-8 to the solution, stir for 30 min, and obtain a milky white solution.

[0038] Step S2: Take 8.72 g Ni(NO 3) 2 6H 2 O, 3.75 g Al(NO 3 ) 3 9H 2 O, 0.26 g Ce(NO 3 ) 3 6H 2 O, dissolved in deionized water, stirred for 30 min to fully dissolve the salt solution, added the salt solution dropwise to the milky white solution, added precipitant ammonia water, adjusted the pH to 9.5, stirred evenly, transferred the above solution to a centrifuge cup, and centrifuged at 4500 r / min for 3 min to obtain the product. The product was centrifuged again with distilled water, washed to neutrality, and then dried in an oven to obtain a green solid powder. Finally, it was placed in a muffle furnace and calcined at 500°C for 3 h at a heating rate of 2°C / min to obtain the metal oxide precursor NiO-ZnO@2.5CeO 2 -Al 2 O 3 .

[0039] Step S3: NiO-ZnO@2.5CeO obtained in step S2 2 -Al 2 O 3 The metal alloy catalyst Ni was obtained by reduction at 600℃ in hydrogen atmosphere for 2 h. 3 Zn@2.5CeO 2 -Al 2 O 3 .

[0040] Example 4 A method for preparing a nickel-zinc alloy catalyst doped with a metal oxide additive comprises: Step S1: Dissolve 7.95 g of anhydrous sodium carbonate in 100 mL of deionized water, stir evenly, then add 2.15 g of ZIF-8 to the solution, stir for 30 min, and obtain a milky white solution.

[0041] Step S2: Take 8.72 g Ni(NO 3 ) 2 6H 2 O, 3.75 g Al(NO 3 ) 3 9H 2 O, 0.60 g Ce(NO 3 ) 3 6H 2O, dissolved in deionized water, stirred for 30 min to fully dissolve the salt solution, added the salt solution dropwise to the milky white solution, added precipitant ammonia water, adjusted the pH to 9.5, stirred evenly, transferred the above solution to a centrifuge cup, and centrifuged at 4500 r / min for 3 min to obtain the product. The product was centrifuged again with distilled water, washed to neutrality, and then dried in an oven to obtain a green solid powder. Finally, it was placed in a muffle furnace and calcined at 500°C for 3 h at a heating rate of 2°C / min to obtain the metal oxide precursor NiO-ZnO@5.0CeO 2 -Al 2 O 3 .

[0042] Step S3: NiO-ZnO@5.0CeO obtained in step S2 2 -Al 2 O 3 The metal alloy catalyst Ni was obtained by reduction at 600 °C in hydrogen atmosphere for 2 h. 3 Zn@5.0CeO 2 -Al 2 O 3 .

[0043] The performance of the catalyst prepared in Example 1 was tested.

[0044] Experimental Group 1 The performance of the catalyst prepared in Example 1 was investigated using a fixed bed reactor. The fixed bed reactor had an outer diameter of 12 mm, an inner diameter of 8 mm, and a length of 485 mm. The reactants and products were detected by a gas chromatograph equipped with a thermal conductivity detector (TCD) and a soap bubble flow meter.

[0045] Reaction conditions: 0.05 g of catalyst mixed with 0.5 g of quartz sand was loaded into the constant temperature zone of the fixed bed reactor, heated to 600 °C under Ar atmosphere, and switched to CH 4 / CO 2 / Ar=1.2 / 1 / 7.8 mixed gas, flow rate is 60 mL / min, reaction pressure is normal pressure, where normal pressure refers to one atmosphere, i.e. 1 bar.

[0046] Experimental Groups 2-5 The difference from experimental group 1 is that CH 4 The volume flow ratios are 1.4, 1.6, 1.8 and 2.0 respectively.

[0047] Test Example 1 The precursor green solid powder before calcination in step S2 of Example 1 was characterized.

[0048] Figure 1 is the XRD pattern of the green solid powder precursor in Example 1. Figure 1 It can be seen that the characteristic diffraction peaks of hydrotalcite appear at 2θ of 11.6°, 23.5°, 34.2°, 38.8°, and 60.6°. They are respectively attributed to the (003), (006), (009), (015), and (113) crystal planes of LDHs, proving that the catalyst precursor has an LDHs structure. The characteristic diffraction peaks attributed to ZnO are shown at 2θ of 31.8°, 34.4°, 36.3°, 47.5°, 56.6°, 62.9°, 66.4°, and 67.9°.

[0049] Figure 2 This is a SEM image of the green solid powder before calcination in Example 1. This shows the morphological characteristics of the catalyst before calcination.

[0050] Test Example 2 The metal oxide precursor calcined in step S2 of Example 1 was characterized.

[0051] Figure 3 The metal oxide NiO-ZnO@2.5CaO-Al in Example 1 2 O 3 The XRD pattern of Figure 3 It can be seen that at 2θ of 37.2°, 43.3°, and 62.9°, characteristic diffraction peaks belonging to NiO (111), (200), and (220) crystal planes appeared. As before calcination, at 2θ of 31.8°, 34.4°, 36.3°, 47.5°, 56.6°, 62.9°, 66.4°, and 67.9°, characteristic diffraction peaks belonging to ZnO were not obtained because the CaO component content was small and the particle dispersion was high.

[0052] Figure 4 The metal oxide NiO-ZnO@2.5CaO-Al in Example 1 2 O 3 SEM image of NiO-ZnO@2.5CaO-Al after calcination 2 O 3 The morphology and structure of the catalyst.

[0053] Figure 5 The metal oxide NiO-ZnO@2.5CaO-Al in Example 1 2 O 3 The BET graph, by Figure 5 It can be seen that its adsorption-desorption isotherm is type IV, and an H3-type hysteresis loop appears, indicating that there is a mesoporous structure in the catalyst.

[0054] Test Example 3 The metal alloy catalyst after reduction in step S3 of Example 1 was characterized.

[0055] Figure 6 The metal alloy catalyst Ni in Example 1 3 Zn@2.5CaO-Al 2 O 3 XRD pattern of Figure 6 It can be seen that Ni appears at 2θ of 43.7°, 50.9°, and 75.3° 3 The characteristic diffraction peaks of Zn alloys indicate that the metal oxide NiO-ZnO@2.5CaO-Al 2 O 3 Ni was successfully formed during the hydrogen reduction process. 3 Zn alloy. No Al 2 O 3 The characteristic diffraction peaks of are due to the low crystallinity of the oxide and cannot be detected by XRD.

[0056] Figure 7 The metal alloy catalyst Ni in Example 1 3 Zn@2.5CaO-Al 2 O 3 SEM image of Ni 3 Zn@2.5CaO-Al 2 O 3 The morphology and structure of the catalyst.

[0057] Test Example 4 Figure 8 The catalyst stability test diagram of experimental group 2 shows that the catalyst can stabilize CH 4 The conversion rate is about 46%, CO 2 The conversion rate was about 70% and no carbon deposits were generated, which indicated that the catalyst had good catalytic performance.

[0058] Table 1 is obtained based on the test data of experimental groups 1-5.

[0059] Table 1 Effect of different methane concentrations on Ni 3 Zn@Al 2 O 3 Effect of -2.5CaO catalyst on methane-rich dry reforming reaction As shown in Table 1, the catalyst synthesized by the present invention can still maintain a near-equilibrium CH 4 conversion rate, and high CO 2 Conversion rate, CH 4 Conversion rate and CO2 Conversion rate in CH 4 :CO 2 When it is 1.4, it can reach 46% and 70%, H 2 The ratio of / CO is about 1. The methane-rich dry reforming reaction can change the product synthesis gas (H 2 / CO) ratio.

[0060] Test Example 5 The catalysts in Experimental Group 2 were characterized after stability testing.

[0061] Fig. 9 The XRD pattern of the catalyst after the stability test of experimental group 2 is shown in Figure 2. Fig. 9 It can be seen that after 100 h of reaction, Ni 3 Zn@2.5CaO-Al 2 O 3 Ni in catalyst 3 The peaks of the Zn alloy shifted, with the (111) crystal plane shifting from 43.7° to 42.8°, the (200) crystal plane shifting from 50.9° to 49.8°, and the (220) crystal plane shifting from 75.3° to 73.1°, indicating that it has transformed into an interstitial carbide catalyst. This transformation occurs because the carbon atoms produced by methane cracking enter the Ni 3 In the interstitial lattice of Zn octahedron, interstitial carbon atoms are formed, which expands the lattice and shifts the diffraction peak to a lower angle. The formation of interstitial carbon atoms can avoid carbon deposition caused by the formation of CC bonds during the reaction, thus enhancing the stability of the catalyst.

[0062] In summary, the nickel-zinc alloy catalyst doped with an additive prepared by the present invention can maintain CH 4 With CO 2 The high conversion rate and stability of the product synthesis gas (H 2 / CO) ratio. 4 :CO 2 When it is 1.4, CH 4 The conversion rate is about 46% and CO 2 The conversion rate is about 70%, H 2 / CO ratio is about 1. The Ni formed during the reaction 3 ZnC 0.7 Interstitial carbides can effectively avoid the formation of CC bonds and have good anti-carbon deposition performance. In addition, the catalyst adopts a coprecipitation method, which has a simple production method, low cost, and is easy to industrialize.

Claims

1. A nickel-zinc alloy catalyst doped with a metal oxide promoter, characterized in that: The catalyst is composed of metal Ni, metal Zn, metal oxide Al2O3, doped auxiliary alkaline earth metal oxide or rare earth metal oxide MO n Composition; the molecular formula of the catalyst is Ni x Zn@yMO n -Al2O3, where: x represents the molar ratio of nickel and zinc, y represents the mass fraction of the doping additive, MO n Represents oxides of different alkaline earth metals or rare earth metals.

2. The nickel-zinc alloy catalyst doped with a metal oxide promoter according to claim 1, characterized in that: The molar ratio of nickel to zinc is: 1≤x≤3; The auxiliary agent MO n The mass fraction y is 1 wt%-5 wt%; The content of the metal Ni is 34 wt%-62 wt%; The alkaline earth metal oxide or rare earth metal oxide MO n Includes at least one of MgO, CaO, CeO2, and La2O3.

3. A method for preparing a nickel-zinc alloy catalyst doped with a metal oxide promoter as claimed in claim 1, characterized in that: The steps include: The first step is to prepare an alkaline solution: fully dissolve the soluble carbonate to obtain solution A, and evenly disperse the zinc source ZIF-8 in solution A; The second step is to prepare a metal ion solution: fully dissolve the nickel salt solution, the aluminum salt solution, and the soluble salt containing the metal element M to obtain a solution B; The third step is to synthesize a metal oxide precursor: add solution B to solution A, add a precipitant to adjust the pH to 8-12, stir evenly and let stand, centrifuge and wash until the solution is neutral, dry and then calcine to obtain a metal oxide precursor; The fourth step is reduction: reducing the metal oxide precursor in a H2 atmosphere to obtain the nickel-zinc alloy catalyst doped with the auxiliary agent.

4. The method for preparing a nickel-zinc alloy catalyst doped with a metal oxide promoter according to claim 3, characterized in that: The soluble carbonate in the first step includes sodium carbonate or potassium carbonate, and the concentration of solution A is 1-2 mol / L.

5. The method for preparing a nickel-zinc alloy catalyst doped with a metal oxide promoter according to claim 3, characterized in that: In the second step, the nickel salt includes one or a mixture of nickel nitrate, nickel sulfate, and nickel acetate, and the concentration of the nickel salt solution is 0.5-2 mol / L; the aluminum salt includes one or a mixture of aluminum nitrate, aluminum sulfate, aluminum acetate, and pseudo-boehmite, and the concentration of the aluminum salt solution is 0.5-2 mol / L; The molar ratio of the nickel salt solution to the aluminum salt solution is 3-1:

1.

6. The method for preparing a nickel-zinc alloy catalyst doped with a metal oxide promoter according to claim 3, characterized in that: The soluble salt containing the metal element M in the second step includes any one or a mixture of nitrate, sulfate and acetate, and the concentration of the soluble salt solution containing the metal element M is 0.5-2 mol / L.

7. The method for preparing a nickel-zinc alloy catalyst doped with a metal oxide promoter according to claim 3, characterized in that: The precipitant in the third step includes any one of urea, ammonia water, sodium hydroxide, potassium hydroxide, and a mixed precipitant of EDTA and sodium hydroxide; In the third step, the calcination temperature is 400-600° C. and the calcination time is 2-5 hours.

8. The method for preparing a nickel-zinc alloy catalyst doped with a metal oxide promoter according to claim 3, characterized in that: In the fourth step, the reduction temperature is 400-600° C., the reduction time is 2-5 hours, and the concentration of hydrogen in the reduction environment is 10-100%.

9. A nickel-zinc alloy catalyst doped with a metal oxide promoter as claimed in claim 1, used in a methane-rich dry reforming reaction.

Images